Method of testing incandescent electric lamps



(No Model.)

E. WESTON.

METHOD OF TESTING INOANDESGENT 'ELEGTRIG LAMPS. No. 334,147, PatentedJan. 12, 1886.

WITNESSES: llVl/E/VTOR fwd BY ATTORNEY N. PETERS. Pholo-Lflhagmpher,Washingion. D Cv NITED STATES ATENT FFICEQ- EDWARD WESTON, OF NEWVARK,NEW JERSEY.

METHOD OF TESTING INCANDESCENT ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 334,147, dated January12, 1886.

Application filed October 13, 1885. Serial No. 179,767. (No model.)

To all whom, it may concern.-

Be it known that I, EDWARD WEsroN, a subject of the Queen of GreatBritain, and a resident of Newark, in the county of Essex and State ofNew Jersey, have invented certain new and useful Improvements in Methodsof Testing Incandescent Electric Lamps, of which the following is aspecification, reference being had to the drawings accompanying andforming a part of the same.

My invention consists in a method of testing incandescent lamps orcarbons for the purpose of detecting weak or defective spots in thecarbons when such exist. It is very difficult to detect the presence ofsuch weak or defective spots except by a very critical and carefulexamination. A carbon which even at various stages of incandescenceappears to the eye to emit a perfectly even light may, nevertheless,contain spots of higher resistance than the remaining portions, andthese spots are more highly incandescent, although they may not appearso. The presence of such spots shortens the life of the carbon, as itgives out usually at those points before the rest is impaired.

One method of detecting the presence of weak spots in the carbon I havedescribed in a former patent. intermittent or undulatory current throughthe carbon, by which means the weak spots, becoming more luminous thanthe rest of the carbon, make themselves visible to the eye. I have,however, devised a plan for accomplishing the same object, whichpresents certain advantages over this method, and is much more sure andreliable. This consists in rotating the lamp or the receiver which holdsthe carbon loop on a vertical axis, whereby the loop is revolved, say,eight or ten times a second, the carbon being rendered incandescent by acurrent. This produces the impression of a continuous surface of light,upon which the weak spots, if there be any, appear as bright lines. Itis not necessary to raise the carbon to a very high degree ofincandescence for this purpose, as the weak spots are most easily de-This consists in passing an tected when the carbon as a whole is a dullred.

This method of testing may be effected by any suitable form ofapparatus, and in the drawings I have shown one of such devices.

A is an incandesent-lamp holder. B B are contacts that bear on strips 00 around the holder, which strips are in electrical connection with theterminals of the lamp D. The holder A is carried by a vertical spindle,E, on which is a bevel-gear or friction-wheel, F. This is rotated by anyconvenient means, as by a bevel-wheel and shaft G, driven by cogwheels HK. The lamp D may be any kind of receiver that will contain a carbonwhile it is rendered incandescent or practically so. It is not necessarythat it be revolved precisely on its vertical axis, as this depends uponthe shape of the carbon; but with a lamp and loop of the shape shownthis is evidently the most desirable way. When the current is directedthrough the carbon and it becomes red, it is revolved at a ratesufficient to make the weak spots, if such exist, appear as bands oflight. WVhen such bands appear, it is shown at once that the carbon isdefective, and that it may be expected to give out within a short time.

\Vhat I claim is- 1. The method of testing the carbons of incandescentelectric lamps, which consists in moving. or rotating the carbons whileincandescent at a speed that enables the weak or defective portions,when such exist, to be distinguished by the eye from the other parts ofthe carbon, as set forth.

2. The method of testing the carbon loops of incandescent electriclamps, which consists in rotating the lamp or receiver containing theloop on a vertical axis while the current is directed through the loop,whereby the weak or defective spots, when such exist, are made apparentto the eye, in the manner set forth.

EDWARD XVESTON.

Witnesses:

RICHARD WM. BLOEMEKE, FRANK N. CRANE.

